Alkaline cyanide brass electroplating baths giving about 52 to 56 percent copper in the deposit are employed as a partial or complete substitute for semi-bright nickel deposits in duplex nickel, chromium plating systems [see Plating, 58, Page 1094 (1971)]. In order to obtain a fine-grained, lustrous, semi-bright to bright brass deposit which can be subsequently further plated with bright nickel and chromium, it is necessary to introduce certain organic additives into the plating bath. While these additives, e.g., condensation products of naphthalene sulfonic acids with formaldehyde as in U.S. Pat. No. 3,296,101, give smooth, lustrous deposits as required, the brass deposit itself is internally weakened, so that its internal cohesive or bond strength is easily overcome and, when a subsequent nickel deposit is plated over the brass deposit, the intermetallic bonds of the brass metal are easily ruptured causing peeling of the overlying deposit. This is an undesirable condition from both an appearance and protective standpoint since there is no protection from corrosion where the overlying deposit has peeled away.
In other cases (e.g., U.S. Pat. No. 3,620,937) although brass deposits of sufficient internal cohesive strength are obtained, the low current density areas of the deposit tend to be dull and grainy which in turn results in poor appearance when subsequently bright nickel plated.